A Tooth Profile Design Method for Large Coincidence Internal Gears Based on Circular Meshing Lines

Abstract

The invention discloses a large-overlap-ratio inner engaged gear tooth form design method based on an arc line of action. The line of action designed through the method is an arc connecting an intersection of addendum circles of an inner gear and an outer gear and an intersection of nodal circles, and on the basis of a plane engagement theory, a conjugation equation expressing the corresponding relation between the line of action and an inner engaged gear conjugate profile curve is established; conjugate profile curves according with the arc line of action are established, wherein the conjugate profile curves are the inner gear addendum profile curve and the outer gear addendum profile curve; the conjugation principle is used for establishing dedendum profiles conjugated with the addendum profile curves and the inner gear dedendum profile is shaped; and transition curves between the gear dedendum profiles and dedendum circles are designed. The method has the beneficial effects that the overlap ratio is high, compared with an involute tooth form, the overlap ratio is increased more than twice, multiple gear teeth are involved in engagement, bearing capacity is high, dynamic impact is small, the relative sliding ratio is low, and the lubricating condition is good; and the profile interference problem is avoided and gear parameters are designed more freely.

Description

technical field [0001] The invention belongs to the technical field of transmission gear design, and relates to a method for designing the tooth shape of an internal meshing gear with a large coincidence degree based on an arc meshing line. Background technique [0002] Internal meshing gear transmission is an important transmission form of gear transmission. It transmits power and movement in the same direction. Compared with external meshing gears, it can reduce the power loss caused by the relative sliding of conjugate tooth profile curves. It has high transmission efficiency and large overlap. , carrying capacity and strength, etc., are widely used in transmission systems such as vehicles. The tooth shapes of internal gears are mainly involute teeth and cycloid teeth. Among them, the involute teeth have been widely used because of their ease of manufacture and interchangeability, and have formed an industrial standard. Restricted by the shape of the teeth, interference ...

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Problems solved by technology

[0004] Aiming at the problems in the design of involute internal meshing gears such as the limitation of the number of teeth, the displacement coefficient, and the small coincidence degree, the present invention provides a method for designing the tooth shape of the internal meshing gear with a large coincidence degree based on the arc meshing line. The meshing gear has a large degree of overlap, and the circular arc connecting the intersection point of the addendum circle of the internal gear and the external gear to the node is used as the design meshing line. According to the meshing principle of the plane gear, the corresponding relationship between the meshing line and the conjugate tooth profile curve of the internal meshing gear is established. Conjugate equation, so as to obtain the conjugate tooth profile curve equation expression satisfying the arc meshing line, the expression describes the tooth top tooth profile curve of the internal gear and the external gear; then, according to the conjugate principle, the structure and the tooth top The dedendum tooth profile curve conjugated to the tooth profile curve; in order to avoid two points contacting at the same time, the tooth root tooth profile curve of the internal gear was modified; finally, the dedendum tooth profile and the dedendum circle of the internal gear and external gear were designed transition arc

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